Papermaking drying drum



Jan. 7, 1964 J. J. KRAUS PAPERMAKING DRYING DRUM 4 Sh eetsSheet 1 Filed July 26, 1960 Jan. 7, 1964 J. J. KRAUS 3,116,985

PAPERMAKING DRYING DRUM Filed July 26, 1960 4 Sheets-Sheet 2 19.64 J. J. KRAUS 3,1 6,985

PAPERMAKING DRYING DRUM Filed July 26, 1960 4 Sheets-Sheet s J. J. KRAUs PAPERMAKING DRYING DRUM Jan. 7, 1964 Filed Jui 26, 1960 4 Sheets-Sheet 4 United States Patent 3,116,985 PAPERMAKING DRYING DRUM James J. Kraus, Neenah, Wis, assignor to Kimberly-Clark Corporation, Neenah, Wis, a corporation of Delaware Filed July 26, 1960, Ser. No. 45,340 3 Claims. (Cl. 34-110) The invention relates to pressure vessels and, more particularly, to drier drums for use in the manufacture of paper.

A paper or tissue forming machine generally comprises a forming wire carrying the wet paper web which is couched from the wire and is partially dewatered by the felts and which is subsequently pressed onto the surface of at least one cylindrical drier drum. These driers are heated by means of steam applied internally of them. In the case of a so-called Yankee type paper machine, only a single drum is used, and the wet paper web is pressed onto the surface of the drum and is dried to the desired final moisture content within a single revolution of the drum. The Yankee machine differs from the conventional Fourdrinier paper machine in that the latter has a number of smaller drier drums, and the paper is transferred from one drier drum subsequently to the others. The paper may be removed or creped from the large Yankee drier dr-um by means of a doctor blade which rides on the surface of the drum.

The present invention is concerned particularly with drier drums on which a doctor blade is applied and which are of large size, being of the Yankee type specifically. More particularly, the invention is concerned with such drums that are of high heat conducting material. Drier drums in the past usually have been constructed of cast iron, and the doctor blades in contact with them have been steel. Cast iron and steel me some-what compatible when there is rubbing action between the two materials, there being a slight lubricating action between them. Due particularly to this reason, the wearing of cast iron drums by steel doctor blades has been uniform enough over the complete drum length to be no major source of trouble.

It has previously been proposed to make the cylindrical drum surface of welded sheets, preferably with the welds extending diagonally with respect to the axis of the drum, such as proposed in the application of C. G. R. Johnson for Paper Making Machine, Serial Number 699,704, filed November 29, 1957, now Patent No. 3,052,039, issued September 4, 1962. It has also been proposed to manufacture the drum of an aluminum bronze, with both the metal sheets and also the welds being of this material. Aluminum bronze is softer than cast iron but transmits more heat than does cast iron, rendering it particularly suitable from the latter standpoint for drier drum usage. In general, the welds are more brittle than are the sheets; and, therefore, the welds have been placed diagonally, so that the doctor blade is continuously in contact with at least one of the welds for minimizing wear. It has been found in actual usage, however, that there has been some non-uniform wear of the drum due to doctor blade action, occurring particularly just beyond the welds on the outer edge areas of the drum which do not carry the paper web. Such undue wear does not occur on the drum surface carrying the paper sheet due apparently to the lubricating action of the paper debris that is carried by the drum in those areas over which the paper web extends and due apparently also to the fact that the paper web in being creped from the drum has the action of tending to separate the doctor blade from its contact with the drum.

It is an object of the present invention to provide an improved welded drier drum construction which is more economical to construct than previous welded drier drums and which has all of the welds beneath the paper web that is carried by the drum, so that the lubricating action ice of the paper web is effective in all welded and immediate ly adjacent areas on the drum surface.

More particularly, it is an object of the present invention to provide an improved drier drum construction in which the welds are substantially peripheral, the drum being made up of a plurality of substantially cylindrical sections welded together.

The invention consists of the novel constructions, arrangements and devices to be hereinafter described and claimed for carrying out the above stated objects, and such other objects, as will 'be apparent from the following description of preferred forms of the invention, illustrated with reference to the accompanying drawings, wherein:

FIG. 1 is a partial elevational view of the terminal end of a papermaking machine including an end view of a Yankee drier drum embodying the principles of the invention and which is made up of a plurality of cylindrical sections placed end to end;

FIG. 2 is a partial side view of the Yankee drier drum and associated parts;

FIG. 3 is a longitudinal sectional view of the drum;

FIG. 4 is a fragmentary longitudinal sectional view on an enlarged scale of the drum;

FIG. 5 is a side view of a pair of rolls for forging one of the sections of which the drum is composed;

FTG. 6 is a sectional view of a roll which is grooved so as to form a flange on one of the end sections of the drum;

FIG. 7 is an elevational view of the drum;

FIG. 8 is a sectional view on an enlarged scale of a welded seam between two dnum sections and taken on line 88 of FIG. 7; and

FIG. 9 is an elevational view of a drum of modified construction.

Like characters of reference designate like parts in the several views.

Referring now to the drawings, and, in particular, to FIGS. 1 and 2, there is illustrated fragmentarily, a typical Yankee type paper machine, particularly the dry end of the machine, which includes a drier drum 10. The drum is supported by a supporting frame 11 resting on a suitable foundation 12. The wet paper web 13 is adapted to be applied to the outer surface of the drum having its edges 14 spaced :a few inches from the edges of the drum and being dried by the drum during a single revolution thereof.

The drum 10 includes a cylindrically welded shell 15 having flanges 15 which are bolted to heads 17. The heads 17 enclose the ends of the shell and are provided with aligned axial openings which receive a hollow shaft 18.

The drum is mounted for rotation by journalling ends of the shaft 18 in bearings 19 secured to the frame 11. The drum 10 is driven by any suitable prime mover, such as a motor 20, shown diagrammatically in FIG. 1 and connected to the shaft 18. The shaft 18 is formed of two hollow axially aligned sections 21 and 22 which are separated by a separator plate 23. The separator plate is provided with a thickened rim 24, and a series of openings 25 extend through the rim and communicate with the interior of the shell 15. Steam nozzles 26 are threaded into the openings 25 and serve to distribute steam from the interior cavity 27 of the shaft section 21 to the interior cavity 28 of the drum 10. I

For removing steam condensate from the drum 10, a pair of scoops 29 are secured to the ends of pipes 30 which extend radially through openings 31 in the shaft section 22.

For providing additional heat to dry the paper web on the surface of the drum 10, a heated hood 32 is secured to the frame 11 and extends around the upper portion of the drum 10. Hot air inlets 32a and suitable outlets (not shown) are provided in the hood for the entry and discharge of the air or other heating medium.

The wet paper web to be dried is carried by a felt web 33 which travels around rolls 34. The paper web is forced against the surface of the drum by a pressure roller 35 which is rotatably mounted in brackets 36 attached to an arm 37. The arm 37 is pivoted at 38 to the fname 11, and the pressure roller 35 is forced against the surface of the drum 10 by a ram 39 of a hydraulic cylinder 40 which bears against the arm 37. The dried paper web is removed from the surface of the drier shell by a creping doctor which includes a doctor blade 41 which is removably secured from within a doctor blade holder 42. The ends of the holder 42 are provided with shafts 43 which are rotatably mounted from within guide blocks 44. The blocks 44 in turn are each mounted within a slide assembly 45 attached to a pivot frame 46 pivotally carried by frame 11. The doctor blade holder 42 and the blade 41 are pivoted by a toggle mechanism 47 which is attached through a lever arm 48 to one of the shafts 43. In addition, a spring loading mechanism 49 of any suitable detailed construction is connected through the toggle mechanism 47 to provide a resilient contact for the doctor blade 41 against the surface of the drier drum 10.

In addition to the vertical and pivotal adjustment for the doctor blade 41, the doctor blade is adapted to oscillate in a direction parallel to the axis of the drum 10. The oscillating motion is provided by an eccentric drive which is shown generally at 50 connected to one of the shafts 43. The oscillating motion is permitted by a loose fit between the pivot frame 46 and the frame 11 and permits the doctor blade to move back and forth across the surface of the drum 10 as the drum 10 rotates to prevent uneven wear of the blade 41.

The drum shell 15, as illustrated particularly in FIGS. 3 and 7, comprises cylindrical drum sections 51, 52 and 53 and generally cylindrical end sections 54 and 55. The sections 51, 52 and 53 are welded together along seams 56 and 57 which extend peripherally of the sections 51, 52 and 53 on planes perpendicular to the axis 58 of the shell and shaft 18. The two end sections 54 and 55 are respectively fixed to the sections 51 and 53 by welded seams 59 and 60 which also extend peripherally and in planes perpendicular to the axis 58. It will be noted that the end sections 54 land 55 are cylindrical except for the inwardly extending flanges 16 that are formed integrally with the remainder of the end sections 54 and 55. The complete shell 15, as has been previously described, has the heads 17 bolted to it within its ends.

The completed drum 10 may be on the order of 12 feet in diameter and its Walls may be about two inches thick, for example. The sections 51-55, and also the other parts of the drum, including the shaft 18, are preferably formed of an aluminum bronze alloy which may have the specific compositions and which may be made in accordance with the metallurgical processes described in the co-pending application of John F. Klement for a Welded Wrought Aluminum Bronze Article and a Method of Heat Treating the Same, Serial No. 682,577, filed September 9, 1957, now Patent No. 2,937,965, issued May 24, 1960. In brief, the alloy may contain 5 to 8 percent of aluminum, .05 to 4 percent of iron, .01 to 5 percent of nickel, .01 to 5 percent of manganese, .01 to 2 percent of tin, .01 to 5 percent of zinc and the balance of copper. The composition of the Welding material is substantially the same as the other parts of the drum, having, however, a slightly greater amount of aluminum, such as 8 percent to 11 percent, in view of the fact that a small amount of aluminum is lost during the welding procedure. The parts 5155 are forged or Wrought as will be described, While the other parts of the drum 10 are cast.

The welds of the seams 56, 57, 59 and 60 are preferably made within an annular cavity or channel between adjacent drier drum sections having a cross section roughly in the form of an hour glass, such as shown in FIG. 8. Each of the sections 51-55 on its ends adjacent others of the sections is provided with a central flat rim portion 61, a curved outwardly opening rim portion 62 adjoining the external surface of the drier section, and a curved inwardly opening rim portion 63 adjoining the inner surface of the section. The rim portions 61, 62 and 63 of adjacent drum sections provide the hour glass shaped channel between each two adjacent sections as is apparent from FIG. 8. The welded seams 56, 57, 59 and 69 are provided by welding the hour glass shaped channels between the drum sections full with weld metal, filling the inwardly opening inner portions of the channels from the inside of the shell sections and filling the outwardly opening external parts of the channels from the outside of the sections. Subsequently to welding of the shell sections 50-55 together, the completed drier shell 15 is internally bored and is externally turned, so that the internal and external surfaces are quite uniform. The shell 15 may then be externally ground so that the external surface of the shell is uniform Within rather close limits.

The center shell sections 51, 52 and 53 may individually be formed from relatively thick-walled hollow cylindrical blanks 64 of the aluminum bronze alloy above referred to. Each cylindrical blank 64 may be initially formed in any suitable manner such as by casting. The blank 64 may then be forged, subsequent to heating, to lengthen it peripherally as well as axially by rolling it between two rolls 65 and 66, which are made to forcefully bear on the blank 64 while the rolls are being turned and gradually brought together. The rolling action is continued until the desired diameter and Wall thickness of a shell section are obtained. Each of the sections 51, 52 and 53 then has its rim portions 61, 62 and 63 cut into it for subsequently welding. The two end sections 54 and 55 are forged in the same manner as the intermediate sections 51, 52 and 53, except that the inner roll, such as the roll 65a illustrated in FIG. 6, is provided with a peripheral groove 67 for forming the inwardly extending flanges 16 as the blank 64 moves between the rolls.

It is contemplated that the paper web 13 is sulficiently wide that its edges 14 cover all of the welded seams 56, 57, 59 and 60, so that the lubricating action of the paper with respect to the seams shall be effective for each of the seams. Such a drum 10 may have a length of about inches, for example, and the intermediate sections 51, 52 and 53 may have lengths of about 40 inches. In this case, the length of each of the end sections 54 and 55 is slightly less than 10 inches; and the edges 14 of the paper may be about 6 inches, for example, from the ends of the drum 10, so that the paper web covers the end welds 59 and 60.

Although, as has been explained, the doctor blade 41 is made to oscillate slightly and, in this manner, the welded seams 56, 57, 59 and 60 during rotation of the drum 10 do not make contact with exactly the same parts of the doctor blade, for reducing Wear patterns in both the blade and drum; nevertheless, if desired, in order to assure the absence of such wear patterns, the embodiment of the drum 10a shown in FIG. 9 may be used. In this embodiment of the drum, the sections 51a, 52a, 53a, 54a and 55a forming the shell 15a are respectively the same as the sections 51, 52, 53, 54 and 55 in the first embodiment, except that the adjoining ends of the sections 51a, 52a, 53a, 54a and 55a are cut on a bias. The seams 56a, 57a, 59a and 601:, at the top of the drum as illustrated in FIG. 9, may, for example, be a distance x, such as one inch, closer to the right end of the drum as seen in FIG. 9 than at the bottom of the drum, and the seams preferably lie on planes that are at angles to the drum axis. Each of the seams 56a, 57a, 59a and 60a thus move axially at the doctor blade 41 as the drum 10a revolves, independent of the oscillating movement that the doctor blade has of itself; and thus any undue wear or lack of wear, in comparison to the Wear of the doctor blade on the drum sections themselves, is distributed for greater lengths of the doctor blade than with the previous embodiment of drum. Greater uniformity of wear of the drum a and the doctor blade 41 may thus be expected with this drum embodiment 10a.

In operation, the paper web is disposed on the lower surface of the lower pass of the felt 33 and travels with the web 13 around the lower felt roll 34 to the pressure roll 35. At the pressure roll 35, the paper web transfers from the felt web 33 onto the outer surface of the drum 10 or 10a and rotates with the drum Within the heating hood 32, so that the paper web is substantially completely dried by the time it reaches the doctor blade 41 from its damp condition at the point of application at the pressure roll 35 to the outer surface of the drum. The doctor blade 41 scrapes or crepes the paper web from the external surface of the drum, and the paper web is then rolled on suitable rolls (not shown) for storing purposes. For securing the correct pressure of application of the doctor blade 41 on the surface of the drum 10 or 10a, the spring loading mechanism 49 may be manually adjusted.

In view of the fact that the welded seams 56, 57, 59 and 60 or 56a, 57a, 59a and 60a are all located beneath the surface of the paper web 13, the doctor blade 41 is lubricated by the paper debris that is carried by the drum underneath the paper web, and no undue non-uniform wearing of the drums may be expected. The doctor blade does not pass abruptly from a welded area to a non-welded area and vice versa, and it thus can be expected that the doctor blade will not dig in to cause cavities when moving from one area to the other. With both drum embodiments, the doctor blade 41 is preferably oscillated; and the seams 56a, 57a, 59a, and 60a in the second embodiment effectively move axially with respect to the blade 41 at the point of blade application to the drum due to the fact that the seams are on a bias, so that the wear of the drum 10a and blade 41 is very uniform.

I wish it to be understood that the invention is not to be limited to the specific constructions, arrangements and devices shown and described, except only insofar as the claims may be so limited, as it will be understood to those skilled in the art that changes may be made Without departing from the principles of the invention.

What is claimed is:

1. In a papermaking machine drier drum doctor blade combination, a generally cylindrical drier drum shell having a smooth external surface to dry a web of paper thereon, a doctor blade in contact with said shell to doctor 6 the web from the drum as the shell is rotated, a pair of shaft sections on opposite ends of the drum for support ing the drum and a head on each end of the drum for joining said shaft sections and shell, said shell comprising a plurality of cylindrical sections which are welded together end to end at seams lying in planes substantially perpendicular to the axis of said shaft sections and at least the outer pair of said cylindrical sections being seamless circumferentially so that the doctor blade outside of the confines of a paper web which overlies said seams operates on a seamless surface.

2. In a papermaking machine drier drum doctor blade combination, a generally cylindrical drier drum shell having a smooth external surface to dry a web of paper thereon, a doctor blade in contact with said shell to doctor the web from the drum as the shell is rotated, a shaft for rotatably supporting the drum, a pair of heads fixed with respect to said shell adjacent the ends of the shell and joining the shaft with respect to the shell, said shell comprising a plurality of cylindrical sections which are welded together end to end at seams lying in planes substantially perpendicular to the axis of said shaft to form the complete shell and which are seamless circumferentially so that a seamless surface is presented to the doctor blade as the drum rotates.

3. In a papermaking machine drier drum doctor blade combination, a generally cylindrical drier drum shell having a smooth external surface to receive a web of paper thereon and dry the web, a doctor blade in contact with said shell to doctor the web from the drum as the shell is rotated, a pair of coaxial shaft sections on opposite ends of the drum for supporting the drum and means for joining said shaft sections and shell to form the drum, said shell comprising a plurality of cylindrical sections which are seamless circumferentially and which are welded together end to end at seams to form the complete shell, each of said seams lying in a plane substantially perpendicular to the axis of said shaft sections.

References Cited in the file of this patent UNITED STATES PATENTS 2,151,048 Rowe Mar. 21, 1939 2,328,321 Berry Aug. 31, 1943 2,338,847 Hansen Jan. 11, 1944 2,429,293 Peck et a1 Oct. 21, 1947 2,519,105 Blue Aug. 15, 1950 2,948,061 Carstens Aug. 9, 1960 3,020,120 Loliger Feb. 6, 1962 3,052,039 Johnson Sept. 4, 1962 FOREIGN PATENTS 824,659 France Nov. 18, 1937 1,215,934 France Nov. 23, 1959 

1. IN A PAPERMAKING MACHINE DRIER DRUM DOCTOR BLADE COMBINATION, A GENERALLY CYLINDRICAL DRIER DRUM SHELL HAVING A SMOOTH EXTERNAL SURFACE TO DRY A WEB OF PAPER THEREON, A DOCTOR BLADE IN CONTACT WITH SAID SHELL TO DOCTOR THE WEB FROM THE DRUM AS THE SHELL IS ROTATED, A PAIR OF SHAFT SECTIONS ON OPPOSITE ENDS OF THE DRUM FOR SUPPORTING THE DRUM AND A HEAD ON EACH END OF THE DRUM FOR JOINING SAID SHAFT SECTIONS AND SHELL, SAID SHELL COMPRISING A PLURALITY OF CYLINDRICAL SECTIONS WHICH ARE WELDED TOGETHER END TO END AT SEAMS LYING IN PLANES SUBSTANTIALLY PERPENDICULAR TO THE AXIS OF SAID SHAFT SECTIONS AND AT LEAST THE OUTER PAIR OF SAID CYLINDRICAL SECTIONS BEING SEAMLESS CIRCUMFERENTIALLY SO THAT THE DOCTOR BLADE OUTSIDE OF THE CONFINES OF A PAPER WEB WHICH OVERLIES SAID SEAMS OPERATES ON A SEAMLESS SURFACE. 